Screens of the yeast activation domain array have been proposed for a number of Gal4 DNA-binding domain fusions constructed from products of genes involved in the DNA damage checkpoint. Screens of Rad9, Rad17, Rad53, and Mec3 are now under way. We have also constructed Gal4-DNA binding domain hybrids for several other checkpoint gene products including Pds1, Mec1, Dun1, Pol30, and Rad24 which we plan to use in array screens.